Men face new charges over Qld teen's death

Beautiful and brave, Cole Miller has become another young man killed by a single punch to the head after allegedly being attacked in the street by two men looking for a fight.

The 18-year-old promising water polo player died in hospital on Monday from massive brain trauma after being hit in Brisbane in the early hours of Sunday.

Alleged attackers Armstrong Renata and Daniel Jermaine Lee Maxwell have had their charges upgraded to unlawful striking causing death, instead of the lesser charge of grievous bodily harm.

The pair, both 21, are due to return to the Brisbane Magistrates Court on Tuesday to face the upgraded charges.

It's alleged Cole and a friend were approached by Renata, Maxwell and two others at about 3.30am on Sunday in Fortitude Valley's Chinatown Mall.

Maxwell asked if the pair wanted to fight before throwing a punch at both young men, according to police allegations summarised in court on Monday by duty lawyer Tim Clements.

"It's then alleged that (Renata) has come in from behind or from the side and that's the punch that has led to (Cole) falling to the ground," Mr Clements told the court.

Cole was on track to follow in the footsteps of his water polo Olympian brother Billy before the fatal blow to the back of the head.

Within hours of Cole's life support being turned off, his father Steven fought back tears to deliver a heartbreaking tribute to his son.

"Cole was a beautiful, brave young man with his whole life left to be lived," he said.

"He has struggled bravely in the intensive care unit of the Royal Brisbane Hospital and our family and many close friends have been by his bedside since the incident."

He represented Queensland's under-20s and played for the Brisbane Barracudas in the national water polo league.

Brisbane's upcoming games in Melbourne and Adelaide have been postponed out of respect for the Millers.

In a statement, the club said members' thoughts and prayers were with the family.

"Cole Miller was in the prime of his life, a talented young water polo player reaping the rewards of his hard work and dedication to the sport he loved," it said.

Detective Acting Inspector Thomas Armitt said the tragic event was a stark reminder of why the One Punch Can Kill campaign began in 2007 following the death of Queensland teenager Matthew Stanley.

"There could be no better advertisement right now as to why that campaign exists," he told reporters.

In Sydney, teenagers Thomas Kelly and Daniel Christie were killed by one punch attacks in 2012 and 2013.

Magistrate Terry Gardiner refused bail for Maxwell, whose parents live in New Zealand, citing an unacceptable risk he would flee or reoffend.

Renata did not apply for bail.